In vitro fitness change of respiratory syncytial virus Palivizumab escape mutants
- VernacularTitle:呼吸道合胞病毒单克隆抗体逃逸株体外适合度变化
- Publication Type:Journal Article
- Keywords: Respiratory syncytial virus; Escape mutant; Fitness; Competitive replication
- From: Chinese Journal of Microbiology and Immunology 2008;28(12):1103-1106
- CountryChina
- Language:Chinese
- Abstract: Objective To assess the fitness of two Palivizumab(PZ)-resistant respiratory syncytial rimses (RSV) strains(F212 and MP4) in HEp-2 cells. Methods A mixture was made with equal amounts of F212 and A2 rims and subcuhured continuously in cell cultures. During cultivation the ratio of F212/A2 was measured by differential plaque assay, nucleotide sequence analysis and restriction fragment length poly-morphism at different time points. Because the replication levels of A2 and MP4 in cell cultures or in cotton rat lungs were similar, the mixtures of A2/MP4 birus at the ratios of 1: 1, 10: 1, 100:1 and 1000:1 were in-oculated respectively in HEp-2 ceil cultures for the comparison in competitive replication. The relative amount of MP4 or A2 was tested by differential plaque assay and nucleotide sequence analysis at different time points. Results During continuous subeultures of F212/A2 at 1: 1 ratio, F212 disappeared nearly at the 10th passage indicating its fitness was lower than that of A2 rims. Among all groups of rims mixtures with various ratios except for 1000:1 group, the MP4 rims became predominant, which showed that the fit-nets of MP4 was higher than that of A2. Conclusion The mutant virus strain MP4 is of more fitness than that of A2 rims in both in vitro and in vivo competitive rephcation. Understanding the increase and decrease mechanisms of mutant rims fitness could be useful for the research of attenuated vaccine.